Gas control system and apparatus



Feb. 6, 1934. G. A, TUK 1,946,043

' GAS CONTROL SYSTEM AND APPARATUS Filed Nov. 30, 1931 INVENTOR. flea/ye A7. 706/4 Patented Feb. 6, 1934 UNITED STATES PATENT OFFICE Application November 30, 1931 Serial No. 578,013

'3 Claims.

This invention relates generally to systems and apparatus for controlling supply of fuel gas to various appliances, as for example domestic heating furnaces, or hot'water heaters. It has .5 particular application to systems of this char acter in which a pilot burner is utilized for effecting ignition of a primary burner.

It is a general object of the invention to devise a gas control system which will adapt itself to various domestic installations, and which will preclude the possibility of gas being supplied. to a primary burner when the pilot burner has become extinguished.

It is a further object of the invention to de- 15 vise a system and apparatus of the above character. having a minimum of working parts, which can be readily installed and adjusted, and which will make use of certain parts now common in domestic heating installations, as for example electrically controlled valves.

Further objects of the invention will appear from the following description in which the preferred embodiment of my invention has been set forth in detail in conjunction with the accmpanying drawing. The appended claims, in which the invention is defined, are to be accorded a range of equivalents consistent with the state of the prior art. 7

Referring to the drawing: H V

Fig. 1 is a diagrammatic view, partly in cross section, illustrating my complete system and apparatus.

Fig. 2 is a plan view, illustrating the relationship between the pilot burner of my apparatus, and a primary burner of a heating appliance.

Referring to Fig. 1 of the drawing, the apparatus shown therein consists of a pilot burner associated with the primary burner 11 of a gas appliance, such as a domestic heating furnace or a hot water heater. A suitable casting 12 serves to support pilot burner 10 and certain other associated parts. The particular form of'burner 10 illustrated consists of a tube 13, having its lower portion threaded into casting 12, and having a flame tip 14 secured to its upper end. The passageway 16 through the tube 13, communicates with the bore 17 in the flame tip, and the flame tip is provided with a slot 18 so that a fan-like flame is produced. Gas supply pipe 19 connects a thermostatic element 24, preferably in the form of a bimetallic strip 25 bent U-shaped as illustrated. One end of this strip is shown fixed to lug 26, provided on casting 12, While the other end is suitably connected to a flexible motion transmitting member, such as a steel wire 27. Thus in the construction illustrated the free end of bimetallic strip 25 carries a member 28, which is apertured to receive the end of wire 27. Set screw 29 is threaded into member 28, and serves 05 to adjustably grip wire 27.

The parts of the apparatus just described are preferably located within the combustion chamber of a furnace or other gas appliance with which the apparatus is being employed. Certain m other parts of the apparatus, to be presently described, are preferably located at some convenient point outside of the combustion chamber. Wire 27 is extended to this other apparatus and in order to properly protect it, it is shown housed primary burner 11, consists of a body 38, which connects with pipe 19, tube 31, and tube 36 through fittings 39, 40, and '41 respectively. Formed within body 38 there is a bore 42, provided with a suitable liner 43, forming a cylinder. Slidably fitted within liner 43, there is a piston 44, which is apertured to receive the extended end of wire 27. Set screw 46, threaded into piston 44, serves to fix the wire to the piston. Formed within body 38 there is also a valve seat 47, one

side of which has communication with pipe 19 by way of duct 48, the other side of which has communication with the interior of liner 43 by way of duct' 49. A valve member 51' of the needle type, cooperates with seat 47, and it can be controlled by an external knob 52. Body 38 is also provided with another valve seat 53, one side of which communicates with tube 36 through duct 54, and the other side of which communicates with a pipe 56, by way of duct 57. A valve member 58 of the needle type cooperates with seat 53, and this valve member is likewise threaded into body 38 and controlled by external knob 59. Passageway 60 serves to establish communiits cation between the inflow side of seat 53 and the interior of liner 43. Dependent upon the temperature of bimetallic strip 25, piston 44 assumes certain positions with liner 43, as will be presently explained.

In addition to controlling flow of gas through certain passages or ducts within body 38, movements of piston 44 are also utilized for controlling an electrical valve, which in turncontrols supply of gas to the primary burner 11. .In Fig. 1 I have diagrammatically illustrated a gas control valve 63, which can be of the electrical solenoid type in which the valve member is normally biased towards closed position, but moved to open position by application of electrical current. This valve is indicated as being connected to a gas supply line 64, and to a line 66 supplying the main burner 11. The electrical winding of this valve is connected serially with-an electrical circuit indicated generally at 67. A suitable supply of current for this circuit can consist of the secondary of an alternating current'step down transformer 68. Likewise serially connected with this circuit, there is a thermostat 69, which is generally located at a remote point, and which is controlled for example by temperature of air in a room or dwelling being heated. Thermostats of this character are Well known in the art, and utilize contacts'which are opened and closed in accordance with the temperature of air.

Control of circuit 67, by movements ofpiston 44, is accomplished by contact means which can be constructed as follows:--As illustrated in Fig.

'1, an insulating bushing 71 is shown fitted within body 38, and in alignment with the cylinder formed by liner 43. Slidably fitted within bushing '71, there'is a plunger 72, the inner end of whichforms an electrical contact. A suitable binding post or terminal connector-'73 is mounted upon the outer end'of bushing 71, and is-connected to circuit 67. A "compression spring 74 serves to urge plunger 72 inwardly. When piston 44 is moved sufficiently far in one direction, set

screw 46 contacts'with plunger 72, and since'this plungeris connected with binding post 7 3 through "spring '74, then the wire of circuit 6'7 connected with binding post 73 isgrounded through body 38.

Operation of the complete system illustrated in Fig. 1 can be explained briefly as follows:-When in normal'operation,'withthe pilot burner 10 igthrough valve seat 4'7 and thence through pipe 19 to the pilot burner. The size of the pilot burner flame can be adjusted by changing the Needle valve member 58 at this time is closed. If the contacts of thermostat 69 are now closed, electrically. operated valve 63 is actuated'to permit flow of gas to the primary burner 11. [burner flame becomes extinguished from some setting of needle valve member 51.

If the pilot cause, as for example an abnormal reduction of gas pressure, or by an abnormal draft, bimetallic strip is permitted to cool so that its free end assumes the position illustrated in Fig. 1 in solid lines. Piston 44 is correspondingly moved to the .fposition likewise illustrated in solid'lines, tointerrupt communication between ducts and 49,

"said contactsareopened to disrupt said electricali circuit, a recycling gas burner cooperating with said: pilot burner andsaid thermostatic: means,

will-re-ignite the pilot burner flame, before bimetallic strip 25 has had an opportunity to cool. Obviously when piston 44 has moved to the positionillustrated in solid lines, no flow of gas can occur to either the pilot or the primary burner, and therefore there can be no danger of i an'explosion, due to accumulation of combustible gas'in the combustion chamber. To recycle the system, the operator opens needle valve member 58, to permit gas to flow from port 34, and. this gas is then manually ignited to produce aflame to heat bimetallic strip 25. 'Upon heating of thisstrip, it is flexed to the position illustrated in dotted lines'toxagain permit flow ofgasto the pilot burner, at which time the pilot burneris ignited by the flame from: the recycling burner.

Following such recycling the operator closes needle valve member'58.

-I claim:

1. In a control system, .a primarypgasburnern a pilot burner associated with the primary. burner, a movable valve memberIfor controlling the supply of gas to the pilot burner,:thermostatic means cooperably positioned. with. respect .to said pilot burner for actuating saidvalve member to;

shut off the supply ofthe gas to the pilot burner when the flame of the same becomes extinguished, an electrically actuated valve for controlling. the supply of gas to the primary burner, an electrical control circuit for said valve, contacts connected with said circuitand-positioned: to be-actuated by movement of said valve member, whereby when said valve-member is moved in a direction tointerrupt supply of gasto the pilot burner,

said recycling burner being arranged to heat said thermostatic means and'to likewise ignite the pilot plying gas tosaid-recycling burner.

2. In a control system, a primary gas'burner, a pilot burner associated'with the primaryburner, a movabletvalve' member for controlling the disrupt said electrical'circuit a recyclingburner cooperatingwith said pilot burner and said'thermostatic: means, "said -:-recycling burner being.

'- arranged to' heat said thermostatic means and. to likewise ignitethe pilot'burner, and manually controlled-valve means for controlling supply of gas to said recycling burner, said last burner, and-manuallycontrolled means for supnamed valve-means, said -valve member, and said contacts, being connected together as a single structural unit.

3. In a control system, a primary gas burner, a casting to be positioned adjacent the primary burner, a thermostatic element carried by the casting, a pilot burner likewise carried by the casting and positioned to ignite the primary burner and to heat the thermostatic element, a recycling burner likewise carried by the casting and positioned to heat the thermostatic element and to ignite the flame of the pilot burner, a movable valve member remote from the primary burner for controlling the supply of gas to the pilot burner, a mechanical connection between the thermostatic element and the valve member to cause the valve member to be actuated to shut off the supply of gas to the pilot burner when the flame of the pilot burner becomes extinguished, an electrically actuated valve for controlling the supply of gas to the pilot burner, an electrical control circuit for said valve, contacts connected with said circuit and positioned to be actuated by movement of said valve member, whereby when said valve member is moved in a direction to interrupt supply of gas to the pilot burner, said contacts are opened to disrupt said electrical circuit, and manually control means for supplying gas to the recycling burner.

GEORGE A. TUCK. 

